Microwave-Induced Molecular Rearrangements. Flash Thermolysis in the Gas-Phase and in Solution: Synthesis of Quinolones and Naphthyridones

3- and 4-Pyridyliminopropadienones were prepared by flash vacuum thermolysis of Meldrum’s acid derivatives and characterized by low temperature IR spectroscopy. They react with dimethylamine to afford 1,5-, 1,6-, and 1,7-naphthyridones. The same naphthyridones are also obtained by microwave irradiation of the Meldrum’s acid derivatives. Quinolones were obtained by microwave irradiation of phenylaminomethylene-Meldrum’s acids and 1-phenylpyrrole-2,3-diones.